1. Field of the Invention
Embodiments of the present disclosure generally relate to power conversion and, more particularly, to a method and apparatus for power conversion with maximum power point tracking utilizing dual feedback loops.
2. Description of the Related Art
Solar panels have historically been deployed in mostly remote applications, such as remote cabins in the wilderness or satellites, where commercial power was not available. Due to the high cost of installation, solar panels were not an economical choice for generating power unless no other power options were available. However, the worldwide growth of energy demand is leading to a durable increase in energy cost. In addition, it is now well established that the fossil energy reserves currently being used to generate electricity are rapidly being depleted. These growing impediments to conventional commercial power generation make solar panels a more attractive option to pursue.
Solar panels, or photovoltaic (PV) modules, convert energy from sunlight received into direct current (DC). The PV modules cannot store the electrical energy they produce, so the energy must either be dispersed to an energy storage system, such as a battery or pumped hydroelectricity storage, or dispersed by a load. One option to use the energy produced is to employ one or more inverters to convert the DC current into an alternating current (AC) and couple the AC current to the commercial power grid. The power produced by such a distributed generation (DG) system can then be sold to the commercial power company.
PV modules have a nonlinear relationship between the current (I) and voltage (V) that they produce. A maximum power point (MPP) on an I-V curve of a PV module identifies the optimal operating point of the PV module; when operating at this point, the PV module generates the maximum possible power output for a given temperature and solar irradiance. Therefore, in order to optimize power drawn from a PV module, it is imperative that the PV module is biased at an operating voltage corresponding to the MPP (i.e., the MPP voltage). Additionally, the PV module operating voltage must be rapidly adjusted to compensate for changes in solar irradiance and/or temperature that impact the MPP.
Therefore, there is a need in the art for a method and apparatus for efficiently operating a PV module at an MPP.